Concerns for both the environment and worker health and safety have prompted almost every industry to explore novel and innovative technologies to reduce or eliminate volatile organic compounds (VOC) from their applications. Volatile organic compounds are organic chemicals that have sufficient vapor pressures under ambient conditions to significantly vaporize and enter the atmosphere. Common sources of VOC include compounds such as those used in dry cleaning and other cleaning processes, in painting and staining applications, and in the processing and use of materials for construction. Other sources of VOC can be found in the processing, dispensing, and use of petroleum fuels.
Although the specific definition can vary, a VOC is generally taken to be any volatile compound of carbon with the exception of carbon monoxide, carbon dioxide, carbonic acid, metal carbides, metal carbonates, and certain other carbon-containing compounds that have no or negligible photoreactivity under ambient atmospheric conditions. Some VOC having more than negligible photoreactivity react with nitrogen dioxides in the air to form ozone, which has been deemed to pose a health threat by causing or exacerbating respiratory problems. Some VOC emitted from paints, stains, varnishes, shellacs, other coating materials as well as plastics, carpets, and other building materials can pose a threat to persons in an indoor environment. Indoor VOC emission is often considered to be a factor in “sick building syndrome.”
Commercial finishing operations typically apply large volumes of coating materials to various types of products. These products include, but are not limited to, furniture, raw and finished lumber, and architectural building materials (e.g., trims, moldings, cabinetry, flooring, and the like). These coating materials may be either water- or solvent-based, and VOC can be emitted from either.
The coating materials that are applied include paints, stains, varnishes, and the like. Each of these materials generally includes a solvent in which pigments (paints), dyes (paints and stains), and resin (varnish) are dissolved or suspended. These solvents are typically carbon compounds having considerable volatility (thus putting them into the VOC category), thereby making them subject to regulation or targets for elimination.
The paints, stains, varnishes, etc. as described above may also include VOC-containing binders. One particular type of VOC-containing binder commonly used is an alkyd-based material. Alkyds are typically manufactured from acid anhydrides (e.g., phthalic, maleic anhydride, and the like) and polyols (e.g., glycerol, pentaerythritol, and the like) and are modified with unsaturated vegetable oil. The unsaturated sites in the oil molecules oxidize, thereby causing polymerization or cross-linking. In the processing of alkyd-based compositions, specifically those in which alkyds are incorporated into paints, stains, varnishes, and the like, the alkyds are undesirably released into the atmosphere.
What is needed is a composition that can be applied to architectural building materials, such a composition having no VOC emissions but that exhibits suitable and desirable properties relating to covering, curing, hardness, and durability.